<!DOCTYPE html>
<html lang="zh_cn">
<head>
    <meta charset="UTF-8">
    <meta http-equiv="X-UA-Compatible" content="IE=edge">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <title>Document</title>
</head>
<body>
    <button>fetch</button>
    <script>
        const btn = document.querySelector('button');
        btn.onclick = function(){
            fetch('http://127.0.0.1:8000/fetch', {
                method:'POST',
                Headers: {
                    name:'atguigu',
                },
                body:'username=admin',
            }).then(respond => {
                return respond.json();
            }).then(value => {
                console.log(value);    
            });
        }
    </script>
</body>
</html>